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Java > Open Source Codes > org > apache > bcel > generic > FieldOrMethod


1 /*
2  * Copyright 2000-2004 The Apache Software Foundation
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  * http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  *
16  */
17 package org.apache.bcel.generic;
18
19 import org.apache.bcel.classfile.ConstantCP;
20 import org.apache.bcel.classfile.ConstantNameAndType;
21 import org.apache.bcel.classfile.ConstantPool;
22 import org.apache.bcel.classfile.ConstantUtf8;
23
24 /**
25  * Super class for InvokeInstruction and FieldInstruction, since they have
26  * some methods in common!
27  *
28  * @version $Id: FieldOrMethod.java 386056 2006-03-15 11:31:56Z tcurdt $
29  * @author <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
30  */
31 public abstract class FieldOrMethod extends CPInstruction implements LoadClass {
32
33     /**
34      * Empty constructor needed for the Class.newInstance() statement in
35      * Instruction.readInstruction(). Not to be used otherwise.
36      */
37     FieldOrMethod() {
38     }
39
40
41     /**
42      * @param index to constant pool
43      */
44     protected FieldOrMethod(short opcode, int index) {
45         super(opcode, index);
46     }
47
48
49     /** @return signature of referenced method/field.
50      */
51     public String JavaDoc getSignature( ConstantPoolGen cpg ) {
52         ConstantPool cp = cpg.getConstantPool();
53         ConstantCP cmr = (ConstantCP) cp.getConstant(index);
54         ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());
55         return ((ConstantUtf8) cp.getConstant(cnat.getSignatureIndex())).getBytes();
56     }
57
58
59     /** @return name of referenced method/field.
60      */
61     public String JavaDoc getName( ConstantPoolGen cpg ) {
62         ConstantPool cp = cpg.getConstantPool();
63         ConstantCP cmr = (ConstantCP) cp.getConstant(index);
64         ConstantNameAndType cnat = (ConstantNameAndType) cp.getConstant(cmr.getNameAndTypeIndex());
65         return ((ConstantUtf8) cp.getConstant(cnat.getNameIndex())).getBytes();
66     }
67
68
69     /** @return name of the referenced class/interface
70      * @deprecated If the instruction references an array class,
71      * this method will return "java.lang.Object".
72      * For code generated by Java 1.5, this answer is
73      * sometimes wrong (e.g., if the "clone()" method is
74      * called on an array). A better idea is to use
75      * the getReferenceType() method, which correctly distinguishes
76      * between class types and array types.
77      */
78     public String JavaDoc getClassName( ConstantPoolGen cpg ) {
79         ConstantPool cp = cpg.getConstantPool();
80         ConstantCP cmr = (ConstantCP) cp.getConstant(index);
81         String JavaDoc className = cp.getConstantString(cmr.getClassIndex(),
82                 org.apache.bcel.Constants.CONSTANT_Class);
83         if (className.startsWith("[")) {
84             // Turn array classes into java.lang.Object.
85 return "java.lang.Object";
86         }
87         return className.replace('/', '.');
88     }
89
90
91     /** @return type of the referenced class/interface
92      * @deprecated If the instruction references an array class,
93      * the ObjectType returned will be invalid. Use
94      * getReferenceType() instead.
95      */
96     public ObjectType getClassType( ConstantPoolGen cpg ) {
97         return new ObjectType(getClassName(cpg));
98     }
99
100
101     /**
102      * Return the reference type representing the class, interface,
103      * or array class referenced by the instruction.
104      * @param cpg the ConstantPoolGen used to create the instruction
105      * @return an ObjectType (if the referenced class type is a class
106      * or interface), or an ArrayType (if the referenced class
107      * type is an array class)
108      */
109     public ReferenceType getReferenceType( ConstantPoolGen cpg ) {
110         ConstantPool cp = cpg.getConstantPool();
111         ConstantCP cmr = (ConstantCP) cp.getConstant(index);
112         String JavaDoc className = cp.getConstantString(cmr.getClassIndex(),
113                 org.apache.bcel.Constants.CONSTANT_Class);
114         if (className.startsWith("[")) {
115             return (ArrayType) Type.getType(className);
116         } else {
117             className = className.replace('/', '.');
118             return new ObjectType(className);
119         }
120     }
121
122
123     /** @return type of the referenced class/interface
124      */
125     public ObjectType getLoadClassType( ConstantPoolGen cpg ) {
126         return getClassType(cpg);
127     }
128 }
129
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